Hello,

Can anyone tell me some factual information on the occurrence of HD? Let me explain. I was told that HD is only 15% hereditary. I took this to mean (due to the conversation) that dogs that had HD in their ancestors might still not get HD and that they only had a 15% chance of getting it or passing it along. Is this baloney or true?

Any information you could provide would be greatly appreciated. If it helps, the breed in question or being discussed were Belgian Malinois. I don't know if that info will help determine the answer, but I thought you should know. Thanks in advance.

Respectfully,

Lesli

I have heard similar numbers when speaking of HD in GSDs. Supposedly the SV has done studies that show only 25% of the occurence of HD is genetic. In other words, if the nutrition, exercise and environment is not correct the HD will manifest itself.

Don't overfeed, feed an appropriate high quality diet, do NOT overexercise young dogs (hard to accomplish with a Malinois!!!).

Here are some links I found with some fairly general info on HD.
http://www.atlanticstates.org/dysplasa.htm

http://www.acmepet.com/canine/genetic/article/chd4.html

Thank you both. Deanna writes: "The conversation you were having sounds like someone making an excuse to breed an animal that didn't pass.

The sad thing with HD is that there seems to be no rhyme or reason to the dogs it affects. Dogs can come from generations of good hips and still not pass. However, I don't think that is enough reason to breed dogs with a dysplastic rating, no matter how mild..."

Actually, it was not someone trying to justify or make an excuse of an animal that did not pass. The dog in question had full passing health clearances. I am aware of a specific line of Malinois that has a high incidence of HD in their lineage. While to my knowledge none of the HD effected dogs have ever been bred, the siblings from the first and second generations have been bred extensively, with people having knowledge of the high occurrence of HD within those lines.

My question was why would you breed to a dog who's sire (if you bred to a first generation) or grandsire (if you bred to a second generation) was known to consistently produce HD? The answer was that HD is only 15% hereditary and that dogs from lines with no occurrence of HD can still throw HD dogs, so why not?? This answer baffled me, so I wondered if there was anything to back it up.

Again, thank you both for your answers and links. Very interesting information. From what I have read, I guess in some ways the person was correct in their response, however I just feel that it is asking for trouble, even though the dogs bred were not the affected littermates, I think that breeding to lines known to be affected is risky. Even with all the health clearances in place, legitimately, it is risky in my eyes.

But then all breeding is risky and a crap shoot at best. We hope for the best of both worlds, and then deal with what we get. Fortunately there are many choices for all of us and forewarned is forearmed.

Thanks again for your answers.

Respectfully,

Lesli

The herability of HD is about 25-45%, depending which measuring methods you use, because the genetic factor still is high HD could be successfully reduced if you select against it.

The reason why even parents that have benn declared as HD-free still could get affected offspring is becausae there is no certain limits between the different grades, a dog could get rated as hd-free but still being close to the line of a remark on HD. If you breed two dogs with mild dysplasia in general half of the pups will have the same status as the parents and the other half will be worser than the parents. So if two dogs are being breed which have no HD-remarks but still are close to a remark, half of the puppies will show sign of HD and the rest will have the same status as the parents. But if you choose a breedingdog which are free from HD, his parents to and his littermates, then this dog probaly will producing good hips, he have really good hips, otherwise his close relatives would be affected. Which such information on the relatives of the dog you could be quite safe that he are on the upperlevel of the HD-free scale.

In sweden there was a stateowned facility that breed labs and GSDs for servicework, about 50 gsds litters a year, they had problems with that nearly 50% of the GSDs showed some sign of hd, from mild to severe. They introduced the following rules for breedingdogs,
1. They should be hd-free
2. Their parents also hd-free
3. not more than one of the littermates to the breedingdog should be allowed to show signs of HD.

With this simple rules, the frequency of HD was reduced from 50 to under 10% in just 10 years. Similar sucess have been done in many breeds in sweden because we have open registres and owners of and breeders of many breeds worked closely with the vets to make sure that as many dogs as possible was screened for hd, which made it possible to see which dogs who was likely to produce HD. But it´s important to rember that screening of HD could be subjective, one reason to the success in sweden could be that we had one experienced vet that judged all x-rays in all breeds, so subjective opinions was low.
So it´s important two differ between breedingdogs and workingdogs, a workingdog could have mild dysplasia but still be a good worker, but if he is used in the breedings he are probaly going to produce HD-affected offspring. As always HD and other diseases are very unlikely to spread in a breed if only healthy dogs with normal structure are being used, and no massproducing of puppies from single dogs are done.

Stig, that sounds like a cool plan. I missed one thing, did the Swedish run kennel not test for HD before they started the program at all. Or they didn't use dogs that were checked?

I think I like the idea of the restrictions of not breeding dogs who's littermates show a high occurance of HD.

This facility had breed dogs only for service since the 30s, but in the 70s they started to work with a project with different experts to solve the problems with HD. When they analyzed all breedings that been done it showed that even dogs that was HD-free produced quite lots of dysplastic dogs. This is HD becuase works as a bell curve, mate two hd-free dogs who are close to have a remark, then half of the puppies will get worser than the parents. The bottomline is that even dogs that been rated hd-free could be close to having mild dysplasia, because there are no strict limits betwenn the different grades. But if both the breedingdogs and their close relatives are free, then you could be quite sure that the breedingdogs really hyave good hips, otherwise more of the close relatives would be affected.

Thanks again for all the information. For me then, from what I've read above, even though the dog in question is unaffected himself, since he comes from lines with high occurrence of HD in siblings (as well as aunts/uncles), then he should not be bred, nor should the littermates, and as long as I stay away from these lines, I should be fine. Correct?

Thanks much for the factual and non emotional information.

Very Respectfully,